Liquid fuel burners



April 3, 1962 A. G. IMBER LIQUID FUEL BURNERS FiledApril 11, 1957 9173mm r G [PM Attorneys United States Patent 3,027,934 LIQUID FUEL BURNERS Alfred Gregory Imber, Chorleywood, England, assignor,

by mesne assignments, to Aladdin Industries Limited,

Greenford, England, a British company Filed Apr. 11, 1957, Ser. No. 652,258 Claims priority, application Great Britain Apr. 16, 1956 2 Claims. (Cl. 158-69) This invention relates to liquid fuel burners applicable to such purposes as the heating element in a domestic boiler, a boiler for the heating system of a building or a space heater.

According to the present invention there is provided a liquid fuel burner comprising a central air supply tube, an annular vaporizing trough surrounding said tube and into which a controlled fuel supply is introduced and a deflector spaced from the exit of said tube which is adapted to deflect at least a portion of the air in the direction of the vaporizing trough.

An embodiment of the invention together with a modification thereof will now be described with reference to the accompanying drawings, of which FIG. 1 is a sectional elevation of a burner,

FIGS. 2 to 4 are enlarged plans of the three deflector elements of the burner, and

FIGS. 5 and 6 are sectional elevations of modified for-ms of burner.

Referring to FIG. 1, the burner comprises an annular vaporizing trough 1 whose inner boundary is constituted by the exterior of a central air supply tube 2 which may be made in two pieces as shown in FIG. 1 for convenience or in one piece as shown at 2a in FIG. 5. Fuel is supplied to the trough '1 via a conduit 3, the supply being controlled, if desired, automatically as by thermostatic means. In order to break up the vapour a gauze ring may be incorporated in the trough 1 or alternatively the trough may contain a wick 4.

Mounted above the open top end of the air supply tube 2 is a first deflector 5, also shown in FIG. 2, which takes the form of a dished plate having its concave side facing the open end of the tube. By means of this deflector the draught through the tube 2 (which may be produced or aided by a mechanical blower) causes part of the flame to be deflected back in the direction of the vaporizing trough to produce the heat necessary for vaporizing the fuel. The portion of the deflector 5 lying inwardly of the downwardly turned edge is perforated with a ring of holes 6 so that only a portion of the air is deflected while the remainder can travel upwards.

In accordance with this embodiment there is provided a second deflector which consists of a disc 7 spaced away from the first deflector 5. This second deflector receives and deflects the air passing through the holes 6 in the deflector 5. In order to permit more efficient combustion, a third deflector is provided above and spaced from the deflector 7 and receives secondary air passing through holes 8 in the latter. In order to distribute the air correctly the holes in the deflector 7 are made smaller than those in the deflector 5 and are staggered therewith as shown in FIGS. 2 and 3. This third deflector is shown at '9 and will be seen to be generally similar to deflector 7. The deflector 9 may also be provided with small holes 10 through which passes what may be described as tertiary air.

In order to position the deflectors correctly, they may be conveniently mounted on a screw-threaded rod as shown at 11 guided in a spider 12. and provided with spacing nuts 13, permitting individual adjustment of the deflectors.

In order to produce a turbulent flow of hot gases, a ring 14 is fitted in the upper portion of the vaporizing trough,

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the turbulence being produced by contact of the gases with the underside of this ring.

In accordance with the modified form of the invention shown in FIG. 5 the fuel-containing portion of the vapor izing trough 1a has upwardly flaring sides whereby increased height of the fuel level above the bottom of the trough results in increased liquid surface area of the fuel. By this means, the more fuel that is supplied to the trough via the conduit 3a, the more is vaporized due to the increased surface area and this has been found to produce stable burner operation. The inner periphery of the vaporizing trough is formed by the exterior surface of the central air tube 2a.

A cap 18 with a central aperture 19 may be carried by either form of vaporizing trough so as to enclose the complete burner, this cap as shown in FIG. 1 being broken away to reduce its height for convenience in illustration.

In accordance with a further modified form of the invention an outer wall, or one or more tubes are placed externally of either form of trough and air ports are provided so that air can be drawn past the sides of the latter and caused to enter the burner above the top of the fuel. Referring to FIG. 6 which shows one form which this modification may take, the sides of the vaporizing trough 1a form the inside wall of a double wall, the outer wall being shown at 15. The central air supply tube 2a is provided with a ring of ports 16 and the inner wall of the trough 1a is provided with a second ring of ports 17. The arrangement is such that air is drawn from the central tube via the ports 16 to pass the eX- terior of the inner wall of the trough and to enter the burner via the ports 17 above the top of the fuel.

With the arrangements according to this invention, a smokeless flame is produced with very little excess air.

I claim:

1. In a liquid fuel burner, an air supply tube open at its upper end, means defining a fuel receiving and vaporizing trough surrounding the upper end of said tube so that the surface of the fuel in said trough is upwardly exposed, means supporting three vertically spaced substantially parallel air deflector members above the open top of said tube, at least the lower two deflector members being perforated and located above the open end of the tube and above the level of the fuel in said trough, and means mounting a turbulence producing ring above said two lower deflector members and wholly surrounding the uppermost deflector member.

2. A liquid fuel burner comprising a central air supply tube, means defining an annular vaporizing trough surrounding said tube and having an upwardly extending portion, means for supplying fuel to said trough, a first perforated deflector, means for mounting said deflector above the exit of said tube so as to pass some of the air from the tube therethrough and to deflect some air towards said trough, a second perforated air deflector, means for mounting said deflector above said first deflector to laterally deflect air passing through the perforations of said first deflector, an inwardly projecting ring mounted on said upwardly extending portion of the trough above the level of said second deflector to produce a turbulent flow of hot gases by contact thereof with the underside of said ring, a third deflector, and means for mounting said third deflector wholly within planes passing through said ring to laterally deflect air passing through the perforations of said second deflector.

(Other references on following page) 3 UNITED STATES PATENTS Lyman Feb. 19, 1878 Van Marter Nov. 19, 1907 Kreutzer July 24, 1923 Bianchi et a1 May 12, 1925 5 Inglis Sept. 18, 1928 Fiske Aug. 20, 1929 Sturgis Aug. 31, 1937 Castle et a1. Nov. 18, 1941 Horbetz Nov. 21, 1950 Broady Nov. 10, 1953 Nagel Jan. 14, 1958 

